Aliphatic unsaturated compounds and the process of preparing them



Patented Nov. 8, 1938 UNITED STATES PATENT OFFICE ALIP'HATIG UNSATURATEDCOMPOUNDS AND THE PROCESS OF PREPARING THEM poration of Delaware NoDrawing. Application March 6, 1937, Serial No. 129,489

9 Claims. (Cl. 260-609) This invention relates to new chemical compoundsand to the process of preparing the same. The invention further pertainsto reactions involving halogen-4-butadiene-l, 2 and alkali and alkaliearth metal inorganic compounds and the products derived from suchreactions.

This case is a continuation-in-part oi applicants copending applicationSerial No. 640,326, flied October 29, 1932, which has now matured intoU. 8. Patent No. 2,073,363 issued March 9, 1937.

It has been disclosed in a patent to Carothers and Collins, 1,950,431,patented March 13, 1934, that the reaction between monovinylacetyleneand hydrogen chloride, under certain conditions, yields substantialquantities of chloro-4-butadiene-l, 2 (CH:=C==CHCH:C1), a new compound,which may be obtained in pure form by fractional distillation. Onemethod 01' producing chloro-4-butadiene-1, 2 is illustrated in thefollowing example:

Exlunu A In each of 20 bottles were placed 175 g. of concentratedhydrochloric acid, 25 g. of calcium chloride and 50 g. ofmonovinylacetylene. The bottles were closed and shaken continuously for5 hours, the supernatant oily layers were drawn and combined, washedwith water, stabilized with pyrogallol, dried with anhydrous calciumchloride, and distilled thru a long column. The fractions collectedwere: (1) 74 g. at 30-35 0., (2) 222 g. at 50-75 0., (3) 576 g. at 85-950., (4) 77 g. at 95-120 (1., and (5) 125 g. residue. Fraction (3) waschiefly chloro-4-butadiene-l, 2. On redistillation it yielded 446 g. ofpure product.

This compound has a boiling point of 86-88 C., a refractive index ofabout 1.477 at 20 C. and specific gravity of about 0.991 at 20 C.

It has now been found that this compound contains its chlorine atom inrather loose combination and hence is capable of undergoing manyreactions in which chlorine is replaced by other groups with theformation of new and valuable compounds.

One object of the invention pertains to the preparation of novel4-butadienyl derivatives. Another object pertains to reactions involvinghalogen-4-butadiene-1, 2 and alkali and alkaline earth metal inorganiccompounds and the products derived from such reactions. A further objectrelates to reacting chloro-i-butadiene-l, 2 with alkaline reacting metalinorganic compounds of the group consisting of alkali metal carbonates,alkaline earth metal carbonates, al-

kali metal oxides, alkaline earth metal oxides, alkali metalhydrosulphides, alkaline earth metal hydrosulphides, alkali metalhydroxides, and alkaline earth metal hydroxides These reactions and theproducts obtained thereby are illustrated in the following examples. Itis to be understood that the methods 01 preparation can be varied overwide limits and the examples recorded below are merely by way oiillustration.

Exams 1 Preparation of hydroxy-i-butadiene-i, 2

A solution of 636 g. of sodium carbonate in 1500 g. of water is heatedat Gil-90 C., with 531 g. oi chloro-4-butadiene-l, 2 with constantstirring for 15 hours. During the reaction sodium chloride crystallizesfrom the water. At the end of the reaction the water insoluble layerwhich contains most of the hydroxy compound is separated from the waterlayer and dried with anhydrous sodium sulphate. A further quantity maybe obtained by extracting the water layer and the precipitated sodiumchloride with ether. The product may be purified by fractionaldistillation, the portion boiling from 68-70 C. at 53 mm. pressure beingsubstantially pure hydroxy--butadiene-i, 2. An appreciable amount ofhigher boiling material and also traces of vinylacetylene are formed inthe reaction. If a caustic alkali such as sodium hydroxide is used inplace of the sodium carbonate, the proportion of these by-products isincreased.

Hydroxyi-butadiene-l, 2 is a colorless liquid which boils at l26-8 C. at756 mm. pressure. At 20 C it has a density of 0.918 and a refractiveindex of 1.4759 for the sodium line of the spectrum. It is quite solublein water and very soluble in the common organic solvents. It has apowerful vesicant action on the skin and its vapor has a stronglyirritating effect upon the mucous membranes. It shows a tendency topolymerize when heated. It is readily hydrogenated by means oi. aplatinum oxide catalyst to normal butyl alcohol, and is converted byboiling with strong hydrochloric acid into the originalchloro-i-butadiene l, 2. I1 cuprous chloride is present during thelatter reaction, the isomeric chloride-2-butadiene-l, 3 results.

Other alkali metal carbonates, e. g., potassium carbonate, may be usedin the above example in place of the sodium carbonate. The alkalineearth oxides, hydroxides and carbonates, e. g. CaO, MgO, Ca(0H)z,Mg(OH)2, CaCOa, MgCOa, etc. may also be used. Alkali oxides andhydroxides may also be used, although they produce increase inby-product.

While the hydrolysis of chl0i'o4-butadiene-1. 2 is preferably carriedout in the presence of an alkaline reagent, substantial hydrolysis takesplace by merely heating chloro-4-butadlene-1, 2 with water, the yieldshowever being considerably lower than when an alkali metal carbonate ispresent.

Methozy-d-butadiene-I, 2

One mole of hydroxy-i-butadiene-l, 2 is placed in a flask provided witha stirrer and reflux condenser. Dimethyl sulphate and 50% aqueous sodiumhydroxide are added to the stirred mixture at such a rate that themixture remains constantly alkaline while its temperature does not riseabove 60 C After about 2 mols of dimethyl sulphate has been added themixture is stirred and heated to boiling for about one hour. The methylether of hydroxy-4-butadiene-1, 2 is then separated. dried, anddistilled. It is a colorless liquid boiling at 87 C. to 89 C. and havinga density at 20 C. or about 0.845 and a refractive index for the sodiumline of 1.435. It is readily hydrogenated under conventionalhydrogenation conditions to methyl n-butyl ether.

Corresponding aliphatic ethers such as the ethyl, propyl, and butyl andhigher alkyl ethers can be prepared quite readily in the same way.Preferred alkylating agents are alkyl esters of strong inorganic acids,particularly the alkyl sulphates. e. g., dimethyl sulphate, diethylsulphate. etc., and alkyl halides, e. g., methyl chloride, ethylchloride, methyl iodide, ethyl iodide, etc.

Aromatic ethers of hydroxy-4-butadiene-L2 may be made by treatment 0!chloroi-butadime-1,2 with metallic phenolates.

Chlorocarbonic ester of hydroxg-4-butadiene-1,2

Slightly less than one mole of hydroxy4-butadiene-1.2 is added to onemole of liquid phosgene at about C. It is warmed gently to removedissolved CH1 and excess phosgene. The black residue is washed with coldwater, dried, and distilled. The chlorocarbonate.

is obtained as a colorless liquid boiling at 66 to 68 C. at 57 mm. Itsdensity is about 1.147 and its refractive index for the sodium line isabout 1.465, both measured at C. The yield is 60 to 70% oi the theory.

The chlorocarbonate may also be obtained by passing gaseous phosgeneinto the cold liquid bydroxy-4-butadiene-1,2 until the calculated amounthas been absorbed.

The chlorocarbonate described above is a convenient source for thepreparation 01' urethanes containing the butadienyl radical For example,a 15% solution 01' the chlorocarbonate in benzene is treated with astream 01 dry ammonia, until the gas is no longer completely absorbed.The precipitated ammonium chloride is filtered ad and the filtrate isevaporated in vacuo. The crystalline residue is recrystallized from amixture of benzene and petroleum ether. The pure butadienyl urethane,CHz=C=CHCHaO--CONH:. is thus obtained in the form of white crystalsmelting at 41 to 41.5 0. (copper block).

In a similar manner by treating the chlorcarbonate with dimethylamineand with methyl aniline, respectively the urethanes described below areobtained:

CH: C CHCH2O-CO-N(CH3) a boiling at 59 to 60 C. at 1 mm.

CH2=C=CH-CH2OCO-N(CH3) CuHs liquid boiling at 136 to 137 C. at 2.5 mm.

The urethanes described above are useiul compounds for medicinalpurposes. Other compounds of this class may be obtained by treatinghydroxy-4-butadiene-L2 with alkyl or aryl isocyanates. Thus, one part ofhydroxy-4-butadiene-1.2 is treated with an equivalent amount ofa-naphthyl lsocyanate. A vigorous reaction oc curs, and the mixture onbeing cooled sets to a solid crystalline mass. After being crystallizedfrom benzene the urethane,

liquid mentioned in the paragraph following Example 1. The same productmay be obtained by the action of phosphorous trichloride in pyridinesolution.

Isomerization of hydroxy-i-butadiene-iz A solution of 2 g. of sodium in138 g. of hydroxyi-butadiene-lz is gently refluxed for 8 hours.Distillation furnishes an important fraction consisting of propargylcarbinol,

Propargyl carbinol is already described in the literature (C. R. 146,1035 (1908); Ann. Chim. (8), 27, 162 (1912)). It balls at about 136 C.at 761 mm. and has the specific gravity It gives a triodo derivative,

I2C=CICH2CH2OH melting at 114 C. In addition to propargyl carbinal thereis obtained a considerable amount oi the isomeric alcoholhydroxy-4-butine-2. CH3EC=CCH2OH, boiling at about 139" C. at 761 mm.There is also some syrupy resin produced.

Dehydration o) hudrozy-4-butadieae-L2 Fifty-eight grams ofhydroxy-i-butadiene-LZ is passed in an atmosphere of nitrogen over 100cc. oi granular basic aluminum sulfate during 2 hours at 250 C. From thecondensate there is obtained 37 g. of unchanged carbinol and 8 g. 0!vinyl-acetylene, HCECCH=CH2.

Exam? 2 Butadienyl mercaptan and butadienyl sulfide A solution oi 180 g.of potassium hydroxide in 100 cc. of alcohol is saturated with hydrogensulfide. Two mols (177 g.) of chloro-i-butadieneill 1.2 are then addedwith mechanical stirring while aslowstreamofhydrogensulndeis passedthrough the solution. The reaction evolves considerable heat. Afteraddition of all the chloro compound, the mixture is stirred for 1% hour,then filtered and the iiltrate treated with 2000 cc. of water. The oilwhich separates at the bottom is decanted and treated with a 20%solution oi sodium hydroxide (2 mols). The alkallne solution is washedwith ether to remove the insoluble material. then acidiiied with 15%sulfuric acid and the resulting solution is again extracted with ether.This latter etheral solution contains the mercaptan with a large amountor undistillable material. Butadienyl mercaptan, CHa==O=CHCH:SH, boilsat 53 C. at 90 mm.

NB 1.5482, D? c.9154.

The yield is about 30% 6: the theory.

The material insoluble in alkali gives on distillation butadienylsulfide,

(CH:==OH-CH:)8

a liquid boiling at '72-'14 C. at mm.

N5 1.5561, Di 0.9553.

This is obtained in 11% yield. Butadienyl mercaptan reacts readily withmercuric oxide to give the mercury derivative,

This is illustrated by the following example:

One moi of chloro-4-butadlene-13is added to 2 mols of powdered potassiumhydroxide and the mixture is gently heated until a vigorous reactionsets in. The distillate which collects in the thoroughly cooled receiveris redlstllled and is thus shown to be a mixture of vinylacetylene 1% ofthe theory), chloroprene (12.5% of the theory), and unchangedchloro-d-butadiene-Lil- One mol of chloro-4-butadiene-L2 was added toone mol of sodium butylate in 400 cc. of butyl alcohol during one hour,and the mixture was then refluxed for 2 hours. The volatile productwhich escaped through the vertical condenser was caught in a coldreceiver. On redistillation it gave 75% of the theoretical amount ofvinylacetylene and a small fraction boiling at 20-25 C. This had thenauseating odor and poisonous properties ascribed to butatriene. andwithin minutes at room temperature it had polymerized to an opaquesolid.

The reactions above described produce new compounds never beforedescribed in the literature. They may be used in the synthesis of newcompounds. Thus 2. -butadienyl alcohol (hydroxy- -butadiene-L2) is astarting point for a whole new series of compounds as is shown inExample 1. The mercaptan may be used to prepare sulphonic acid.Butatriene readily polymerizes and may be used as a cross-linking agentin other polymerlzatlons. The mercaptans may be polymerized to givesoluble resins. some of the new compounds are physiologically active andare, therefore, useful as pharmaceutical ingrcdl ents.

In addition to the use of chloro-4-butadiene- 1,2 in the reactionsdescribed above, the invention is intended to include also the use 0!other hologen-a-butadienes-lz e. g., bromo4-butadime-1.2.

The above description and examples are intended to be construed asillustrative only. Any modification or variation thereof which conformsto the spirit of the invention is intended to be included within thescope of the claims.

We claim:

1. The process which comprises reacting hal ogen-4-butadiene-12 with analkaline reactin metal inorganic compound of the group consisting ofcarbonates, oxides, hydrosulfldes, and hydroxides.

2. The process which comprises reacting ch1oro-4-butadiene-12 with analkaline reacting metal inorganic compound of the group consisting ofcarbonates, oxides, hydrosulfldes. and hydroxides.

8. The process which comprises reacting chloro-i-butadiene-LZ with analkaline reacting metal carbonate.

4. The process which comprises reacting chloro-4-butadiene-1,2, with analkaline reactin metal hydroxide.

5. The process which comprises reacting chloro-4-butadiene-L2 with analkaline reacting metal hydrosulflde.

6. A four carbon compound having at least two sets 0! carbon to carbondouble bonds obtainable by the process of claim 2.

7. A compound of the formula CH==C=CHCH:(OH)

B. A compound of the formula 9. A compound of the formulaCHs=C=CH-C'Hz-BH.

WALLACE H. CARDTHERS. GERALD J. BERCHET.

Certificate of Correction Patent No. 2,136,178. November 8, 1938.WALLACE H. CAROTHERS ET AL.

It is hereby certified that errors appear in the printed specificationof the above numbered patent requiring correction as follows: Page 1,first column, line 33, Example A, for 8595 C. read 8095 C.; page 2,first column, line 43, for CH1 read HCl; and second column, line 54, inthe formula, for UH -OH read CH OH; line 58, for the formula CH C=CCHOH" read CH -CECCH OH; line 74, for 100 cc. read 1000 00.; page 3, firstcolumn, line 30, before CH at the beginning of the formula insert aparenthesis; and second column, line 24, for hologen read halogen; andthat the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Ofiice.

Signed and sealed this 20th day of December, A. D. 1938.

[SEAL] Henry Van Arsdale Acting Commissioner of Patents.

